VS9: How can I edit/save unconverted video (WMV & MPEG2)

[arnach]

Nature of the problem: I would like to be able to trim some video files, then save them in the exact same format, without re-rendering them (which always seems to degrade the quality)

Source files: WMV files (from CDs created for us by a video recording house)--Video: WMV v7, 640x480, 24 bits, 30.0 fps; video data rate 1868kbps; Audio: WMA v9, 44.1k, 16bits, stereo

MPEG2 files: from ATI TV Wonder Elite video capture, various bit rates, but typ 8000kbps CBR

Is it possible to do save a portion of a WMV or MPEG2 clip from VS9 without having to re-render the images? I have tried matching the source file settings, but the rendered video always seems more coarse/jaggedy. I have tried both MPEG and AVI project settings, but neither seem any different in the end.

Thanks in advance.

Arn

[Ken Berry]

If you are just after individual files, then after trimming them, I just use Clip > Save Trimmed Video, which will give you a smaller file in exactly the same format. No re-rendering is involved. The original file is also kept should you ever want it again.

This should certainly work with the mpeg-2 files, though I think some people have had trouble when they try it with WMV files. But in theory at least, it is supposed to work with them too. Try it and see.

[arnach]

Thanks, Ken!

I tried your suggestion on a WMV video, and the results were mixed. Where I had previously seen borders get 'jaggy,' this way worked much better. However, in other (non-edge) areas, the image got far worse: blocky i.e. conversion artifacts of some kind. I noticed that the program still went through a '...rendering...' step, because there was a message saying so and it burned a bunch of CPU cycles, which shouldn't have been needed if the video were merely trimmed.


Any other ideas? I'll try it on an MPEG2 as well to see if that works differently.

Thanks again,

Arn

[Ken Berry]

Sorry about that. I had not tried anything with WMV. In fact, I almost never touch the format. Lots of people here report a variety of other problems when they try using VS to edit and process it. As I understand it, it has very complex coding, apart from being a highly compressed format. And I guess both factors make it difficult to edit with any success.

I wonder whether you could use Windows Movie Maker to edit/trim them: after all, that is a Microsoft product which (again in theory at least) should be able to handle well what is also a Microsoft format. (Move Maker of course will not open mpeg-2 files.)

[arnach]

Ken--you da man!

Of course (head slap)--the MS product should work with the MS file format--and it does!

I also don't normally work with WMV, but this time didn't really have any choice--that's the only format they had the video in :-(

Thanks for the tip; too bad it didn't work in VS9.

Thanks again for your time and input.

Arn